NOT SO HOT: Shaun Marcum pauses during a tight moment in last night's 5-1 loss to the Marlins, which snapped the Mets' five-game win streak. Marcum was tagged with the defeat and fell to 0-6 this season.AP

MIAMI — The Mets learned one of life’s hard truths last night: You can’t play the Yankees every game.

Only in the Mets’ bizarro world could they complete a four-game sweep of their hated Subway rival one night and then get smothered by the dreadful Marlins the next.

But Shaun Marcum (0-6) wilted in the seventh inning and the Mets lineup forgot to show up in a 5-1 loss at Marlins Park that snapped a five-game winning streak.

“You’re not going to win 18 straight,” manager Terry Collins said. “You’ve got to take your streaks, and when you get beat start another one.”

The Mets (22-30) had only one solid offensive night in the Subway Series, a fact largely obscured by their dominant starting pitching over four games. But Marcum couldn’t bring the Mets to that level last night, even if he wasn’t as mediocre as his final line of four earned runs on seven hits and two walks over 6 2/3 innings might suggest.

The Marlins (14-31) benefited from bloop singles by Marcell Ozuna and Ed Lucas as part of their four-run outburst against Marcum in the seventh.

“If I’m going to lose, I’d rather make mistake pitches and have them get hit over the fence than make well-located pitches and have them fall in,” Marcum said.

Jacob Turner (1-0) frustrated the Mets over seven shutout innings in which he allowed five hits and did not walk a batter. Struggling Ike Davis finished 1-for-3 with a double, giving him consecutive games with at least one hit. Daniel Murphy’s RBI double in the eighth accounted for the Mets’ only run.

Collins discounted the notion the Mets were fatigued mentally and physically — they arrived at their hotel at 4:30 a.m. yesterday — after such exhilarating games against the Yankees. To give his players extra rest, the manager canceled batting practice and scheduled a later reporting time than normal.

Marcum’s shutout disappeared in the seventh, when the Marlins scored four runs on four hits and a walk. The big hit was Jordan Brown’s two-run double that extended Miami’s lead to 4-0.

Lucas, a 31-year-old rookie, had delivered a bloop RBI single for his first major league hit before Jeff Mathis’ sacrifice fly added another run.

“It’s just one of those nights where [Marcum] kept us in the game and gave us a chance,” Collins said.

“We didn’t mount much offense, but I certainly wasn’t disappointed with the way Shaun pitched, that’s for sure.”

With Jon Niese sidelined by left shoulder tendinitis for at least one start, Collin McHugh will get the ball today hoping to show Mets brass he belongs in the conversation regarding the organization’s young pitching talent.

Maybe the most attention the 25-year-old McHugh has received in 2013 came Thursday in the aftermath of the Mets’ sweep of the Yankees when he tweeted: “You can call the NYC Sanitation Dept. because we just SWEPT the yankees from Queens to the Bronx.” McHugh later removed the tweet because of the backlash he received from fans.

“I was real proud of the way this team was playing so maybe it got ahold of me a little bit,” McHugh said. “But I think the most important thing is we’re enjoying it and having fun. It feels good to win, but I took [the tweet] down because it’s not worth it. I don’t want to distract from anything these guys are doing in here.”

McHugh made eight appearances for the Mets late last season and finished 0-4 with a 7.59 ERA. But he pitched a gem in his major league debut, with seven scoreless innings against the Rockies on Aug. 23. He then struggled through September, allowing 23 hits in 14 innings.

“He started to fall behind hitters, which is not at all how he pitches,” Collins said. “He’s a guy who throws strikes with all his pitches and that’s what has made him successful, and when you get away from that you’re going to have problems.”